In a High Speed Uplink Packet Access (HSUPA) service of a third generation mobile communication system Universal Mobile Telecommunications System (UMTS), an Enhanced Dedicated Channel (E-DCH) symbol-level decoding processing specifically includes a step of de-interleaving, a step of rate de-matching, a step of HARQ combination, a step of Turbo decoding and a step of Cyclic Redundancy Check (CRC) checking, as shown in FIG. 1 which is a flowchart of E-DCH symbol-level decoding. In FIG. 1, the HARQ combination, which is a multi-stop-and-wait parallel retransmission technology combining features of Forward Error Correction (FEC) and Automatic Repeat Request (ARQ), is between the rate de-matching and the Turbo decoding. In a HARQ retransmission mechanism, a User Equipment (UE) sends a data packet, if an NodeB receives the data packet correctly and a CRC checking is correct for the data packet, then a correct decoding indication ACK is returned; otherwise, an error decoding indication NACK is returned. After receiving the NACK, the UE needs to retransmit a corresponding data packet over a physical layer. Information of two or more data packets involved before or after the retransmission is used together in channel decoding, thereby maximizing the success probability of decoding.
An HSUPA E-DCH achieves a HARQ combination by using incremental redundancy technology. For example, as incremental redundancy information providing information for a soft combination of a physical layer is added into the data packet during retransmission, a final coding rate of the whole transmission is reduced even if a coding rate is extremely high in initial transmission, which can achieve an adequate retransmission system gain without bringing any load burden to the system. That is, both a power gain and a coding gain are brought for the system.
A HARQ controlled by the NodeB enables error data to be retransmitted quickly, which reduces a time delay caused by the retransmission over a Radio Link Control (RLC) layer and improves the Quality of Service (QoS) feature of time delay. Moreover, a higher Block Error Rate (BLER) is tolerable on a link, that is, the transmitting power of a corresponding terminal is reduced, as a consequence, more UEs may be supported and the system throughput is accordingly increased on the condition of the same system load.
Even so, existing technologies still have the following technical problems: the existing technologies are unsupportive to a latest interference cancellation algorithm, causing much interference to a UE of high rate, which impacts the performance of HARQ combination; and the existing technologies, which are achieved based on software, are low in data processing efficiency during the transfer process of a large amount of data of Double-Data-Rate Two Synchronous Dynamic Random Access Memory (DDR2) in HARQ combination.